Objective To prepare doxorubicin-loaded pH/magnetic dual responsive nanocomplex denoted as Fe₃O₄@SiO₂@PEG-b-PAsp@DOX and to determine its chemo-physical properties, pH/magnetic dual responsive release, and cytotoxicity against human lung cancer A549 cells. Methods The nanocomplex was synthesized through a sequential process involving hydrothermal treatment, Stber method, sol-gel technique, and cross-linking. The morphology, diameter, zeta potential and magnetic properties of the nanocomplex were characterized by transmission electron microscopy, zeta potential measurement analyzer, and hysteresis loop tester, respectively. Drug loading efficiency and encapsulation efficiency were examined by ultraviolet visible absorption spectroscopy; pH-stimulated drug release was investigated by dialysis in vitro; and the anti-proliferative activity apoptosis-induction effect of the complex nanoparticles were investigated by CCK-8 method and flow cytometer, respectively. Results The average particle size of drug-loaded system Fe₃O₄@SiO₂@PEG-b-PAsp@DOX was (197.7±1.5) nm and the zeta potential was (-35.9±0.6) mV. Drug loading efficiency and encapsulation efficiency were (20.36±0.67)% and (83.71±0.53)%, respectively. Cumulative release rate was significantly increased in mild acid condition (pH=5.5) (P<0.05). The nanocomplex also demonstrated a good magnetic response and targeting ability under outside magnetic field. Moreover, the drug-loaded nanoparticle showed a significant cytotoxicity effect against human lung A549 cells in vitro. Conclusion Fe₃O₄@SiO₂@PEG-b-PAsp@DOX possesses a good pH/magnetic dual responsive release characteristics and exhibits efficient antitumor activity in vitro against lung cancer A549 cells.